Sinker arrangement and control means for circular knitting machine



W66 H. E. CRAWFORD 339 3 SINKER ARRANGEMENT AND CONTROL MEANS FORCIRCULAR KNITTING MACHINE Filed March 1, 1963 4 Sheets-Sheet 1 HERMAN E,QRAWFORB INVENTOR.

I CNN-MM I Dec. 27, T1966 H. E. CRAWFORD 3,293,887

ARRANGEME CONTROL MEANS INE SINKER NT AND FOR CIRCULAR KNITTING MACHFiled March 1, 1963 4 Sheets-Sheet 2 =HE'EMAN E. CEAwFoRb INVENTOR.

Y PQALLQMiiAe ATTORNEYS Dec. 27, 11966 H. E. CRAWFORD 392939837 SINKERARRANGEMENT AND CONTROL MEANS FOR CIRCULAR KNITTING MACHINE Filed March1 1963 4 Sheets-Sheet 5 b R Q P W C E N A M 2 E H m m m m A TTOENE Y5 HE. CRAWFORD 3,293,887 SINKER ARRANGEMENT AND CONTROL MEANS FOR CIRCULARKNITTING MACHINE 4 Sheets-Sheet 4 6 l 6 9 1 1h h m 7 a 2 M Q m e n D FHERMAN E. CRAWFORD INVENTOR.

United States Patent 3,293,887 SINKER ARRANGEMENT AND CONTROL MEANS FORCIRCULAR KNITTING MACHINE Herman E. Crawford, Kernersville, N.C.,assignor to H. E. Crawford Co., llnc., Kernersville, N.C., a corporationof North Carolina Filed Mar. 1, 1963, Ser. No. 262,160 7 Claims. (Cl.66-108) This invention relates generally to an improved sinkerarrangement and control means for circular knitting machines whichincludes a pair of sinkers supported in each of the spaces betweenadjacent needles and control means for selectively operating one of thesinkers independently or operating the pair collectively so that themachine may selectively knit plain fabric, plated fabric, reverse platedfabric, terry fabric or a fabric having loose or elongated stitch loops.

It is well known to utilize a conventional sinker and a special controlelement in each sinker slot of the sinker head of a circular hosieryknitting machine in which the special control element is used to controlthe plating of a pair of yarns as they are fed to the needles. Varioustypes of pattern control means have been provided for selectivelyoperating these special elements to control the plating of the yarns andform a wide variety of designs, however, all of these known arrangementshave been complicated and they do not include means for forming loosestitches in selected portions of the fabric.

With the foregoing in mind, it is a primary object of the presentinvention to provide an improved sinker arrangement and control meanstherefor which arrangement includes a reverse plating sinker and a loosestitch sinker in each slot of the sinker head of a circular knittingmachine and suitable control means for selectively operating one of thesinkers independently or operating the pair collectively whereby theneedles may form plain regular stitches, loose or elongated stitches,plated stitches, reverse plated stitches, or terry stitches.

It is another object of the present invention to provide a sinkerarrangement and control means of the type described which can be easilyand economically applied to existing circular knitting machines andwhich is simple in operation.

It is a more specific object of the present invention to provide asinker arrangement of the type described in which each of the reverseplating sinkers includes a neb, a normal stitch drawing ledge positionedinwardly of the neb, a downwardly and outwardly sloping reverse platingsurface extending from the neb and terminating in a reverse platingstitch drawing ledge positioned outwardly of the neb, and in which eachof the loose stitch sinkers includes a neb having a normal stitchdrawing ledge positioned inwardly of the neb and a loose or elongatedstitch drawing ledge on the upper surface of the neb, the sinkers beingsupported for independent movement of the reverse plating sinkers orcollective radial movement of both types of sinkers between adjacentneedles by sinker control cams carried by the sinker head.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds, when taken in connection withthe accompanying drawings, in which:

FIGURE 1 is a fragmentary plan view of the sinker cap and needle bedplate of a circular hosiery knitting machine and illustrating theimproved sinker arrangement and sinker control cams therefor;

FIGURE 2 is a fragmentary elevation of the sinker cap looking in thedirection of the arrow 2 in FIGURE FIGURE 3 is an isometric view of thetwo different types of sinkers which are positioned in each groove ofthe sinker bed;

FIGURE 4 is a horizontal sectional view through the sinker cap andshowing the sinker control cams positioned to cause both types ofsinkers to move collectively and to position the sinkers where theneedles form plain stitches over the stitch drawing ledges in front ofthe nebs thereof;

FIGURE 5 is a vertical sectional view illustrating the position of thesinkers and the control cam when the yarn is initially taken in thehooks of the needles, being taken substantially along the line 55 inFIGURE 4;

FIGURE 6 is a view similar to FIGURE 5, but showing the position of thesinkers and the control cams after the needles have been lowered tostitch drawing level, being taken substantially along the line 66 inFIGURE FIGURE 7 is a view similar to FIGURE 4 but showing the sinkercontrol cams in position to independently move the reverse plate sinkersinwardly while maintaining the loose stitch sinkers in withdrawnposition;

FIGURE 8 is a vertical sectional view showing the position of the camsand sinkers when the yarns are initially taken in the hooks of theneedles during reverse plating, being taken substantially along the line8-8 in FIGURE 7;

FIGURE 9 is a view similar to FIGURE 8 but showing the position of thesinkers and the control cams after the needles have been lowered tostitch drawing level, being taken substantially along the line 9-9 inFIG- URE 7;

FIGURE 10 is a vertical sectional view through the sinker bed, removedfrom the needle cylinder, and illustrating the horizontal annular groovewhich has been cut therein to accommodate the radially movable lowersinker control cam;

FIGURE 11 is a view similar to FIGURES 4 and 7 but illustrating theposition of the sinkers and control cams when the sinkers are beingcollectively moved inwardly so that the needles may form eitherelongated or terry stitches over the stitch drawing ledges on the topsof the nebs;

FIGURE 12 is a vertical sectional view taken substan-= tially along theline 1212 in FIGURE 11 and illustrating the position of the sinkers whenthe yarn is initially taken in the hooks of the needles;

FIGURE 13 is a vertical sectional view taken substantially along theline 1313 in FIGURE 11 and illustrating the position of the sinkers andcontrol cams after the needles have been lowered to stitch drawinglevel.

The sinker arrangement and control means of the present invention isshown associated with a seamless hosiery knitting machine of thewell-known Scott and Williams type, however, it should be understoodthat the invention is also applicable to other types of circular hosieryknitting machines. Referring to FIGURES 1 and 2, the machine includes acircular bed plate 20 which surrounds the needle cylinder 21 andsupports the usual stitch cams and needle control cams, not shown. The

lower end of the needle cylinder 21 is supported in the conventionalmanner on a bevel gear which is a part of the conventional drivemechanism of the knitting machine, not shown, and which is adapted to attimes rotate and at other times reciprocate the needle cylinder. Theneedle cylinder 21 is slotted vertically to receive independentlyvertically movable latch needles N in a conventional manner.

A sinker bed 22 is fixedly supported on the upper end of the needlecylinder 21 in a conventional manner and is provided with spaced andradially extending grooves or slots 23 (FIGURE which each slidablysupport a pair of sinkers indicated at S and S in FIGURE 3. The sinkersS and S are supported for longitudinal movement inwardly and outwardlybetween the circular series of needles N and their configuration will belater described in detail. As heretofore stated, each of the slots 23 inthe sinker bed 22 has both a loose stitch sinker S and a reverse platesinker S supported for longitudinal movement therein and the forward orinner ends of the sinkers S and S are supported for longitudinalmovement in suitable grooves in an inner sinker ring (FIGURES 5, 6, 8,9, 12 and 13) which is suitably secured to the upper end of the needlecylinder 21 in the usual manner.

A sinker cap 26 is supported on the sinker bed 22 in the usual mannerand contains the usual sinker operating cams, as well as the improvedsinker control cams of the present invention, to control the radialposition of the sinkers as they are rotated with the sinker bed 22. Thesinker cap 26 is held against rotation by the conventional stop lugswhich engage a bunter post, not shown.

A latch ring support post 30 (FIGURE 1) is secured at its lower end tothe bed plate 20 and its upper end pivotally supports the rear portionof the conventional latch ring which in turn supports the yarn feedfingers at the main yarn feeding station, not shown. A plurality ofthrust rods 31 extend upwardly through a plate 32 carried by the latchring post 30 and their upper ends engage and control operation of theyarn feed fingers while their lower ends are engaged by alined cams onthe main pattern drum in a conventional manner.

The sinker cap 26 is provided with the usual sinker end cams 35 and 36which are supported adjacent opposite sides of the knitting position andthey each have respective inwardly inclined cam surfaces 35a and 36awhich are adapted to engage the butts of the sinkers to move the sameinwardly of the sinker head 22, to the normal innermost position betweenthe needles N. It will be noted, particularly in FIGURES 4 and 6, thatthe forward inclined cam surface 36a of the cam 36 is thinner than therearmost portion, for purposes to be later described. It is the normalpractice to support the end cam 36 in a horizontal slot or groove 37 inthe sinker cap 26 (FIG- URE 2).

The end cam 36 is supported for adjustment by suitable screws in thesinker cap 26. Ring earns 40 and 41 are also supported on the sinker cap26 and limit inward movement of the sinker S between the needles N. Asshown in FIGURE 4, the machine is also provided with a center sinkerdraw-back cam 43 which is supported on the sinker cap 26 and itsleft-hand end usually extends over to and meets the free end of the ringcam 41. However, in the present instance, the left-hand end of thecenter cam 43 has been cut off, for purposes to be presently described.

An elastic feed sinker draw-back cam 44 (FIGURE 1) is fixed on theforward end of a control lever 45 which is pivotally supportedintermediate its ends on a shaft 46 that is in turn secured in the latchring support post 30. The rear end of the control lever is engaged by athrust rod, not shown, which is controlled from the main pattern drum.The thrust. rod is raised to lower the cam 44 into a cut-out in thesinker cap 26 where it engages the butts of the sinkers S and S to movethe same outwardly during the time that an elastic yarn is to be inlaidin the knit fabric, in the usual manner. It is the common practice toknit a mock-rib fabric by forming long or loose stitches of the bodyyarn while feeding an elastic yarn to certain of the needles so that itis inlaid in the fabric. The elastic yarn contracts the fabric in acoursewise direction and causes spaced wales of the fabric to protrudeand provide the ribbed appearance, particularly when the fabric isrelaxed.

The parts heretofore described are conventional parts of a circularhosiery knitting machine of the type known as a Scott and Williams andonly so much of the machine has been shown as is necessary to anunderstanding of the present invention. A detailed description of thisgeneral type of machine is given in US. Patent No. 1,152,850 and thispatent may be referred to for a description of the parts not shown inthe present application. However, it is to be understood that thepresent invention is also adaptable for use with other types of circularhosiery knitting machines and is not intended to be limited to theparticular machine shown.

In accordance with the present invention, each of the loose stitchsinkers S (FIGURE 3) includes a neb 50, a normal stitch drawing ledge 51positioned in front of the neb 50 and an operating butt 52. It will benoted that the operating butt 52 extends upwardly from the body of theoutermost portion of the sinker S and its lower edge is cut away belowthe butt 52 and at its outer portion to form a stepped edge or notch 53,for purposes to be later described. Each of the reverse plate sinkers S(FIGURE 3) includes a neb 55, a normal stitch drawing ledge 56positioned inwardly of the neb 55, and an operating butt 57 extendingupwardly from the outermost portion of the body of the sinker S.

The loose stitch sinker S has a fiat loose stitch forming ledge 50awhich is positioned on the top of the neb 50 and extends in a horizontaldirection and parallel to the normal stitch drawing surface S of thesinker S. The reverse plate sinker S is provided with a downwardly andoutwardly extending inclined reverse plate surface 55a which acts toreverse the position of a pair of yarns as they are lowered against theinclined surface 55a in a well-known manner. The upper end of theinclined reverse plate surface extends to the top of the neb 55 and thelower end terminates at a fiat stitch drawing ledge 55b which ispositioned outwardly of the inclined reverse plate surface 55a and theneb 55.

As has heretofore been mentioned, each of the slots 23 in the sinkerhead 22 has one loose stitch sinker S and one reverse plate sinker Spositioned therein. As shown in FIGURE 3, each of the loose stitchsinkers S has a longer or higher operating butt 52 than the butt 57 ofthe corresponding reverse plate sinker S in each slot. The butts 52 and57 as well as the notch 53 are used to control the operation of thesinkers in a manner to be presently described.

The sinker cap 26 is provided with an outwardly extending lug 60(FIGURES 1, 2 and 6) on which a pair of sinker control cams 61 and 62are pivotally supported. The upper control cam 61 will be referred to asa loose stitch control cam and the lower control cam 62 will be referredto as a reverse plate control cam. The cams 61 and 62 are pivotallysupported by a screw 63 which penetrates the two control levers 61 and62 and is threadably embedded in the outwardly extending lug 60. Thesinker control cams 61 and 62 are held in spaced apart and parallelrelationship by spacer 64 (FIGURE 2) on the pivot screw 63. The forwardends of the cams 61, 62 are inclined and form respective sinker controlcam surfaces 61a and 62a (FIGURE 11).

The forward ends of the earns 61, 62 are normally urged to the withdrawnor inoperative position shown in FIGURES 1 and 4 by suitable tensionsprings 71 and 72 which are suitably secured at one end on the free endsof the levers 61, 62 and the other ends of the springs 71, 72 aresuitably secured to the sinker cap 26 (FIGURES 1 and 2). An L-shapedstop member 75 (FIGURES 1 and 2) is adjustably supported on the uppersurface of the sinker cap 26 and has a downwardly depending arm which isadapted to engage the inner surface of a medial portion of the camlevers 61, 62 and limit outward movement of their free ends.

The sinker control cam levers 61, 62 are selectively operated byrespective connecting links 81, 82 which are connected at their innerends to the respective cam levers 61, 62 and their outer ends areconnected to the vertical arms of corresponding bell cranks 83 and 84which are pivotally supported on the latch ring pivot post 30 (FIG- URE1). The horizontal arms ofthe bell cranks 83, 84 are suitably connectedto the upper end of respective thrust rods 85, 86, the lower ends ofwhich engage the conventional main pattern drum, not shown. The mainpattern drum is provided with suitable control cams for selectivelymoving the forward ends of the sinker control cams 61, 62 inwardly tooperative position.

A selectively operable sinker hold-back cam 90 (FIG- URES 1 and 5) ismounted for vertical movement into and out of operative position to, attimes, engage the operating butt 52 of the loose stitch sinkers S toprevent their inward movement while allowing the reverse plate sinkers Sto be moved inwardly in advance of the knitting point. The upper surfaceof the sinker cap 26 has an opening to permit for movement of the cam 90thereinto and the cam 90 is suitably supported on the free end of a leafspring member 92, the other end of which is suitably supported on theupper surface of the sinker cap 26 (FIGURES 1 and 2). The free end ofthe spring 92 is normally biased upwardly to thereby normally maintainthe sinker cam 90 in the inoperative position shown in FIGURE 12.

The free forward end of a control arm 94 overlies the free end of theleaf spring member 92, as shown in FIGURES 1, 2, 5, 8 and 12, and itsrear end is suitably connected to the upper end of a thrust rod 95. Thelower end of the thrust rod 95 is biased into engagement with the mainpattern drum, not shown, and it is at times raised by suitable cams onthe main pattern drum. When the lower end of the thrust rod 95 is inengagement with the main pattern drum, the control arm 94 is lowered tothe position shown in FIGURES 2, 5, and 8 to depress the free end of theleaf spring member 92 and move the sinker control cam 90 downwardly tooperative position Where it will engage only the higher operating butts52 on the loose stitch sinkers S.

As shown in FIGURE 8, the lower sinker control cam 62 is in alinementWith the lower portion of the grooves or slots 23 in the sinker head 22and when this cam 62 is moved inwardly it would engage the outerperiphery of the sinker head 24. Therefore, it has been necessary to cutan annular horizontal groove 23a (FIGURE 10) in the sinker head 22 sothat the sinker control cam 62 can be moved inwardly to the operativeposition.

Operation As has heretofore been explained, when the sinker arrangementand control means of the present invention is utilized, the knittingmachine can selectively knit plain fabric with a single yarn, a platedfabric with a pair of yarns, a reverse plate fabric in which the normalpositions of the two yarns are reversed by the sinkers, a terry fabricwith a pair of yarns or a loose stitch fabric in which an elastic strandis inlaid in either every course or in spaced courses to form a mock ribfabric.

When the machine is to knit a plain fabric of a single yarn or a plainplated fabric of two yarns, both of the sinkers S and S are maintainedin the outermost position until after the needles N have picked up theyarn from the yarn feed fingers and then the sinkers are moved inwardlybetween the needles so that the stitch loops are formed over the normalstitch drawing ledges 51, 56 of the respective sinkers S and S in thenormal manner. In this instance, both of the sinkers are moved inwardlytogether by the inclined cam surface 36a at the free end of the end cam36. Thus, the outer edges of the oper- 6 atin-g butts (FIGURE 4) engagethe cam surface 36a and both sinkers are moved inwardly together whilethe sinker cam is lowered to maintain the sinkers in an outermostposition, asshown in FIGURES 4 and 5.

Both of the sinker earns 61 and 62 are maintained in an outermost orinoperative position as the needles N and sinkers S move in acounterclockwise direction in FIG- URE 4 and all of the sinkers S and Sare moved outwardly by the center cam 43. The sinkers are maintained inan outermost position while the yarn Y (FIGURE 5) is picked up in thehooks of the needles and then as the needles are lowered to stitchdrawing position, the end cam 36 moves the sinkers S and S' inwardly toposition the same where the needles N form stitch loops over the normalstitch drawing ledges 51 and 56 of both sinkers S and S. Then, as theneedles N begin to raise back up to cast OK the previous stitches, thesinkers S reach their innermost position to shed the cast off loops fromthe needles.

The manner in which the sinkers cooperate with the needles N in theformation of a reverse plated fabric and the position of the sinkercontrol cam during this type of knitting is shown in FIGURES 79. As thesinkers S and needles N move in a counterclockwise direction in FIGURE7, they are all withdrawn by the center cam 43 and the lower sinker cam62 is moved inwardly to the operative position shown. Thus, the sinkerengaging cam surface 62a engages the lower portion of the butts of thesinkers S to move the same inwardly as a pair of yarns Y are picked upin the books of the needles (FIGURE 8).

The sinker draw-back cam 90 is in operative position to prevent inwardmovement of the sinkers S while the sinkers S are moved inwardly by thecam 62. The cam 90 extends down far enough to engage the butts 52 on thesinkers S and hold the same in an outermost position but this cam 90does not extend down far enough to engage the short butts of the sinkersS (FIGURE 8). The sinkers S are not moved inwardly by the cam 62 becausethey are provided with the notches 53 which permits the cam 62 to bemoved inwardly to an operative position. As the needles N pick up thepair of yarns Y and lower the same, the reverse plate sinkers S aremoved inwardly to a position where the yarns engage and are rolled downthe inclined reverse plate surface 55a to reverse the normal position ofthe yarns in a conventional manner. Thus, the position of the yarns isreversed when the needles are lowered to stitch drawing position to formreverse plate stitches over the stitch drawing ledges 55b. After thereverse plate stitches are formed, the sinkers S are moved inwardly bythe cam surface 36a of the end cam to aid in shedding the stitches asthe needles are again raised (FIGURE 9).

When it is desired to knit a section of plain plated fabric of a pair ofyarns, it is merely necessary to withdraw the cam 62 from action. Thenboth of the sinkers S and S' will follow the path of travel illustratedin FIG- URE 4 where the needles N will form plain plated fabric and drawthe stitches over the normal stitch drawing ledges 51 and 56 of therespective sinkers S and S.

In order to form a loose stitch knit fabric having a mock-ribappearance, it is the usual practice to withdraw the sinkers at thepoint at which the elastic yarn is fed to the needles to inlay theelastic yarn in the fabric in the usual manner. In the present instancethe sinkers are withdrawn at the elastic feed point by the sinker cam 44(FIGURE 1) and then as the sinkers and needles rotate in acounterclockwise direction in FIGURE 11, the sinkers are again withdrawnby the center cam 43. The upper cam 61 is moved to the operativeposition shown in FIGURE 11 to thereby move all of the sinkers inwardlyat an earlier point than they would be moved inwardly by the cam surfaceof the end cam 36 so that the sinkers are positioned as shown in FIGURE12 as the yarn Y is lowered by the needles N. Both the sinkers S and Sare maintained in the innermost position while the needles are loweredby the usual stitch cams, not shown, to form loose or long stitch loopsover the stitch drawing ledge 50a at the top of the nebs 50 of thesinkers S. During the knitting of this loose stitch fabric, the sinkercam 90 is maintained in inoperative position by raising the thrust rod95 and the control arm 94, as shown in FIGURE 12. It will be noted thatthe cam 61 is positioned to move inwardly against the outer butts of thesinkers and at an elevation above the cutouts 53 of the sinkers S andbelow the upper surface of the operating butts 57 of the sinkers S.

A terry fabric may also be knit with the present sinker arrangement andcontrol means. In this instance the yarn which forms the terry pileloops would be fed at a higher elevation than the yarn which forms theplain knit base fabric. As the sinkers and needles rotate in acounterclockwise direction in FIGURE 11, the upper cam 61 is moved tothe operative position to collectively move the sinkers inwardly at anearlier point than they would be moved inwardly by the end cam 36. Asthe sinkers are moved inwardly, the needles are lowered to form stitchloops of both the terry yarn and the base yarn with the terry yarn beingdrawn down over the stitch drawing ledge 50a at the top of the nebs 50of the sinkers S and with the base yarn being drawn down over the stitchdrawing ledge 51 in front of the nebs 50 of the sinkers S.

Thus, the sinker arrangement and control means of the present inventionmay be utilized to form plain knit fabric or plain plated fabric, in themanner shown in FIGURES 4-6, it may be utilized to form a reverse platefabric, in the manner shown in FIGURES 79, or it may be utilized to forma loose stitch fabric or a terry fabric in the manner shown in FIGURES11-13. It is to be understood that the control cams may be operatedselectively to form successive position of each type of knit fabric in asingle piece of tubular fabric, such as a stocking. Thus, the presentsinker arrangement and control means makes a circular hoisery knittingmachine more versatile and it can be applied to the machine withoutrequiring major modifications thereto.

In the drawings and specification there have been set forth a preferredembodiment of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaims.

I claim:

1. In a circular knitting machine of the type having a circle ofneedles, and a sinker bed surounding the circle of needles, said sinkerbed having radially extending sinker grooves therein which are alinedwith the spaces between said needles, an improved sinker arrangementtherein comprising (a) a pair of sinkers supported for collective andindependent longitudinal movement in each of the grooves of said sinkerbed, each of said sinkers including (1) an upstanding neb positionedintermediate opposite ends thereof,

(2) a normal stitch drawing ledge positioned inwardly of said neb, and

(3) an upstanding operating butt positioned outwardly of said neb,

(b) one of said sinkers in each of the sinker grooves having an elongatestitch drawing ledge on the upper edge of said neb,

(c) the other of said sinkers in each of the sinker grooves having adownwardly and outwardly extending inclined reverse plating surface onsaid neb and a reverse plate stitch drawing ledge positioned at thelower end of said reverse plating surface and outwardly of said neb, and

(d) the operating butt of one sinker in each of the sinker grooves beinglonger than the operating butt of the other sinker in each of the sinkergrooves, and

the outer portion of the lower edge of each longer butt sinker beingundercut to position the outer lower edge of the sinker in spacedrelationship above the bottom of the corresponding groove of said sinkerbed.

2. In a circular knitting machine according to claim 1 wherein saidlonger butt sinkers have said elongate stitch drawing ledges on theupper edge of said nebs.

3. In a knitting machine having a circular series of needles mounted forvertical movement in a rotatable needle cylinder, a sinker bed supportedon the upper end of said needle cylinder and having radially extendinggrooves in alinement with the spaces between the needles in saidcylinder, sinkers supported for longitudinal sliding movement in thegrooves of said sinker bed and between adjacent needles, each of saidsinker elements having a neb, a first stitch drawing ledge positionedinwardly of said neb, and an upstanding operating butt on the outer endthereof, and a sinker cap supported on said sinker bed and having fixedcam means operable upon the butts of said sinkers to control the radialposition of said sinkers and normally position the same for said needlesto form plain stitch loops over said first stitch drawing ledges of thesinkers, the combination therewith of an improvement comprising (a) saidsinkers being arranged in pairs with a pair of sinkers in each of thegrooves of said sinker bed and being supported therein for collectiveand independent longitudinal movement therein,

(b) one of each of said pairs of sinkers having an auxiliary stitchdrawing ledge on top of said neb,

(c) the other of each of said pairs of sinkers having a downwardly andoutwardly extending inclined reverse plating surface on said neb and anauxiliary stitoh drawing ledge positioned at the lower end of saidreverse plating surface and outwardly of said neb,

(d) sinker control means supported on said sinker cap and being movableinto engagement with said sinkers for selectively changing the normalposition of said sinkers relatively to said needles,

(e) pattern control means operatively connected to said sinker controlmeans for selectively controlling said sinker control means to at timesposition said one sinker of each pair for said needles to form elongatedstitch loops over said auxiliary stitch drawing ledge on the top of theneb thereof and to at other times position said other sinker of eachpair for said needles to draw yarns down the inclined reverse platingsurface and form a reverse plate stitch loop over the auxiliary stitchdrawing ledge thereof, and

(f) the operating butt of said one sinker of each pair being longer thanthe operating butts of said other sinker of each pair, and

(g) the outer portion of the lower edge of each longer butt sinker beingundercut to position the outer lower edge of the sinker in spacedrelationship above the bottom of the corresponding groove of said sinkerbed.

4. In a circular knitting machine according to claim 3 wherein saidsinker control means (d) includes (1) a first movable sinker controllever supported for pivotal movement on said sinker cap and having a camsurface positioned to engage the outer ends of said pairs of sinkers andcollectively move the pairs of sinkers inwardly at a point in advance ofthe point at which the pairs of sinkers are normally moved inwardly bysaid fixed cams, and

(2) a second movable sinker control lever supported for pivotal movementon said sinker cap and having a cam surface positioned to engage thelower portion of the outer ends of said other sinkers of each pair andindependently move the same inwardly at a point in advance of the pointatv which the pairs of sinkers are normally moved inwardly by said fixedcams, the cam surface of said second movable sinker control lever beingpositioned in the same plane with the undercut portions of said onesinker of each pair to thereby avoid engagement with the outer ends ofsaid one sinkers.

5. In a circular knitting machine according to claim 4 wherein saidsinker control means (d) further includes a vertically movable sinkercontrol cam supported on said sinker cap and being movable downwardly asuflicient distance to be engaged by the longer butts of said onesinkers and prevent inward movement thereof when said other sinkers arebeing moved inwardly by the cam surface of said second movable sinkercontrol lever.

6. In a knitting machine having a circular series of needles mounted forvertical movement in a rotatable needle cylinder, a sinker bed supportedon the upper end of said needle cylinder and having radially extendinggrooves in alinement with the spaces between the needles in saidcylinder, sinkers supported for longitudinal sliding movement in thegrooves of said sinker bed and between adjacent needles, each of saidsinker elements having a neb, a first stitch drawing ledge positionedinwardly of said neb, and an upstanding operating butt on the outer endthereof, and a sinker cap supported on said sinker bed and having fixedcam means operable upon the butts of said sinkers to control the radialposition of said sinkers and normally position the same for said needlesto form plain stitch loops over said first stitch drawing ledges of thesinkers, the combination therewith of an improvement comprising (a) saidsinkers being arranged in pairs with a pair of sinkers in each of thegrooves of said sinker bed and being supported for collective andindependent longitudinal movement therein,

(b) one of each of said pairs of sinkers having an auxiliary stitchdrawing ledge on top of said neb,

(c) the other of each of said pairs of sinkers having a downwardly andoutwardly extending inclined reverse plating surface on said neb and anauxiliary stitch drawing ledge positioned at the lower end of saidreverse plating surface and outwardly of said neb,

(d) sinker control means supported on said sinker cap and being movableinto engagement with said sinkers for selectively changing the normalposition of said sinkers relative to said needles,

(e) pattern control means operatively connected to said sinker controlmeans for selectively controlling said sinker control means to at timesposition said one sinker of each pair for said needles to form elongatedstitch loops over said auxiliary stitch drawing ledge on the top of theneb thereof and to at other times position said other sinkers of eachpair for said needles to draw yarn down the inclined reverse platingsurface and form a reverse plate stitch loop over the auxiliary stitchdrawing ledge thereof, and

(f) a vertically movable sinker control cam supported on said sinker capand being movable downwardly a sufiicient distance to be engaged by thebutts of said pairs of sinkers and prevent inward movement thereof inadvance of the point at which said pairs of sinkers are moved inwardlyby said fixed cam means.

7. In a knitting machine having a circular series of needles mounted forvertical movement in a rotatable needle cylinder, a sinker bed supportedon the upper end of said needle cylinder and having radially extendinggrooves in alinement with the spaces between the needles in saidcylinder, sinkers supported for longitudinal sliding movement in thegrooves of said sinker bed and between adjacent needles, each of saidsinker elements having a neb, a first stitch drawing ledge positionedinwardly of said neb, and an upstanding operating butt on the outer endthereof, and a sinker cap supported on said sinker bed and having fixedcam means operable upon the butts of said sinkers to control the radialposition 10 of said sinkers and normally position the same for saidneedles to form plain stitch loops over said first stitch drawing ledgesof the sinkers, the combination therewith of an improvement comprising(a) said sinkers being arranged in pairs with a pair of sinkers in eachof the grooves of said sinker bed and being supported for collective andindependent longitudinal movement therein,

(b) one of each of said pairs of sinkers having an auxiliary stitchdrawing ledge on top of said neb, (c) the other of each of said pairs ofsinkers having a downwardly and outwardly extending inclined reverseplating surface on said neb and an auxiliary stitch drawing ledgepositioned at the lower end of said reverse plating surface andoutwardly of said neb,

(d) the operating butts of said one sinker of each pair being longerthan the operating butts of said other sinkers,

(e) the outer portion of the lower edge of each longer butt sinker beingundercut to position the outer lower edge of the sinker in spacedrelationship above the bottom of the corresponding groove of said sinkerbed,

(f) sinker control means supported on said sinker cap and being movableinto engagement with said sinkers for selectively changing the normalposition of said sinkers relative to said needles and including (1) afirst movable sinker control lever supported for pivotal movement onsaid sinker cap and having a cam surface positioned to engage the outerends of said pairs of sinkers and collectively move the pairs of sinkersinwardly at a point in advance of the point at which the pairs ofsinkers are normally moved inwardly by said fixed cams,

(2) a second movable sinker control lever supported for pivotal movementon said sinker cap and having a cam surface positioned to engage thelower portion of the outer ends of said other sinkers of each pair andindependently move the same inwardly at a point in advance of the pointat which the pairs of sinkers are normally moved inwardly by said fixedcams, the cam surface of said second movable sinker control lever beingpositioned in the same plane with the undercut portion of said onesinker of each pair to thereby avoid engagement with the outer ends ofsaid one of said sinkers, and

(3) a vertically movable sinker control cam supported on said sinker capand being movable downwardly a sufiicient distance to be engaged by thebutts of said pairs of sinkers and prevent inward movement thereof inadvance of the point at which said pairs of sinkers are moved inwardlyby said fixed cam means,

(g) pattern control means operatively connected to said sinker controlmeans for selectively controlling said sinker control means to at timesmove said first movable sinker control lever to operative position andcollectively move said pairs of sinkers inwardly for said needles toform elongated stitch loops over said auxiliary stitch drawing ledges onthe top of the nebs of said one sinker, to at other times move saidsecond movable sinker control lever to operative position andindependently move said other sinkers inwardly for said needles to formreverse plate stitch loops on the inclined reverse plate surface andsaid auxiliary stitch drawing ledge positioned outwardly of the nebs ofsaid other sinker, and to at still other times move said verticallymovable sinker control cam to operative position while maintaining saidfirst and second movable sinker control levers in inoperative positionfor said needles to form plain 1 1 1 2 stitch loops over said firststitch drawing ledges posi- 2,310,070 2/1943 Fregeolle 669 tionedinwardly of the nebs of said pairs of sinkers. 3,172,274 3/1965 Anthonyet a1 66-108 FOREIGN PATENTS 5 947,667 1/1949 France.

References Cited by the Applicant UNITED STATES PATENTS 1,796,266 3/1931Lawson et a1. 66-108 MERVIN STEIN, Primary Examiner- 1,977,590 10/1934Page et a1 66-108 W- C. REYNOLDS, Examiner.

1. IN A CIRCULAR KNITTING MACHINE OF THE TYPE HAVING A CIRCLE OFNEEDLES, AND A SINKER BED SURROUNDING THE CIRCLE OF NEEDLES, SAID SINKERBED HAVING RADIALLY EXTENDING SINKER GROOVES THEREIN WHICH ARE ALINEDWITH THE SPACES BETWEEN SAID NEEDLES, AN IMPROVED SINKER ARRANGEMENTTHEREIN COMPRISING (A) A PAIR OF SINKERS SUPPORTED FOR COLLECTIVE ANDINDEPENDENT LONGITUDINAL MOVEMENT IN EACH OF THE GROOVES OF SAID SINKERBED, EACH OF SAID SINKERS INCLUDING (1) AN UPSTANDING NEB POSITIONEDINTERMEDIATE OPPOSITE ENDS THEREOF, (2) A NORMAL STITCH DRAWING LEDGEPOSITIONED INWARDLY OF SAID NEB, AND (3) AN UPSTANDING OPERATING BUTTPOSITIONED OUTWARDLY OF SAID NEB. (B) ONE OF SAID SINKERS IN EACH OF THESINKERS GROOVES HAVING AN ELONGATE STITCH DRAWING LEDGE ON THE UPPEREDGE OF SAID NEB, (C) THE OTHER OF SAID SINKERS IN EACH OF THE SINKERGROOVES HAVING A DOWNWARDLY AND OUTWARDLY EXTENDING INCLINED REVERSEPLATING SURFACE ON SAID NEB AND A REVERSE PLATE STITCH DRAWING LEDGEPOSITIONED AT THE LOWER END OF SAID REVERSE PLATING SURFACE ANDOUTWARDLY OF SAID NEB, AND (D) THE OOPERATING BUTT OF ONE SINKER IN EACHOF THE SINKER GROOVES BEING LONGER THAN THE OPERATING BUTT OF THE OTHERSINKER IN EACH OF THE SINKER GROOVES, AND THE OUTER PORTION OF THE LOWEREDGE OF EACH LONGER BUTT SINKER BEING UNDERCUT TO POSITION THE OUTERLOWER EDGE OF THE SINKER IN SPACED RELATIONSHIP ABOVE THE BOTTOM OF THECORRESPONDING GROOVE OF SAID SINKER BED.